The present invention relates to a pouring device for a dual-roll type continuous casting machine for direct formation of melt into a strip of sheet metal.
Well known in the art are continuous casting machines in which melt such as molten steel is poured into a water-cooled mold to form a casting which is pressed by a plurality of rollers and drawn into slabs, billets or the like. The slabs or billets thus cast are cut into a predetermined length and then transferred through a heating furnace to a rolling mill. As an improvement in the structure of such continuous casting machines for producing slabs, billets or the like, a so-called dual-roll type continuous casting machine capable of forming melt directly into a strip of sheet metal has been devised and demonstrated.
As shown in FIGS. 1 and 2, a dual-roll type continuous casting machine comprises a pair of cooling rolls 1 disposed horizontally and substantially in parallel with each other in a spaced-apart relationship. Side dams 2 are disposed at widthwise ends of the rolls 1. A tundish 4 for pouring melt 3 is disposed above the cooling rolls 1 and a core 5 extends downwardly from the bottom of the tundish 4. A pouring passage 6 for pouring melt 3 is defined through the tundish 4 and the core 5. The pair of cooling rolls 1 and the side dams 2 at the widthwise ends thereof define a basin 7 into which the bottom of the core 5 is immersed. The pouring passage 6 is positioned to open substantially toward a middle point between the axes of the rolls 1. Melt 3 is charged from the tundish 4 through the pouring passage 6 to form a basin 7 where melt 3 is cooled by the pair of cooling rolls 1 to form a solidified shell 8, whereby a casting 9 in the form of sheet metal is continuously cast by rotation of the cooling rolls 1 in the directions indicated by the arrows.
When melt 3 is poured from the tundish 4 through the core 5 into the basin 7 in the dual-roll type continuous casting machine described above with reference to FIG. 1, the pressure or flow rate of melt 3 is so high that contact of melt 3 with the solidified shell 8 which is being formed by the cooling rolls 1 tends to result in re-melting of the solidified shell 8. Such re-melting of the solidified shell 8 will cause variations in thickness, cracking or bulging of the casting 9. It follows therefore that in order to prevent the re-melting of the solidified shell 8, the pressure or flow rate of melt flowing down out of the pouring hole 6 of the core 5 must be decreased and a countermeasure for avoiding direct contact of melt 3 being poured with the solidified shell 8 must be devised.
In view of the above, a primary object of the present invention is to provide a pouring device for a dual-roll type continuous casting machine in which a manifold for temporarily receiving melt from the tundish is disposed within the core so that the pressure or flow rate of melt flowing down out of the core is decreased and direct contact of melt with the solidified shell is avoided.
The above and other objects, features and advantages of the present invention will become more apparent from the following description of preferred embodiments thereof taken in conjunction with the accompanying drawings.